Abstract
Hydroxyurea is a cytotoxic agent indicated in the treatment of a variety of malignant and nonmalignant conditions. Apart from dose-related bone marrow suppression, this antineoplastic agent is generally well tolerated. This report describes a patient with chronic myeloid leukemia who developed severe pneumonitis within four weeks of beginning therapy with hydroxyurea. Pathological examination of a lung specimen obtained by video-assisted thoracoscopic lung biopsy revealed extensive active alveolar and interstitial inflammation, and poorly formed granulomas. After the cessation of hydroxyurea and treatment with systemic corticosteroids, both clinical and radiological resolution of pneumonitis occurred. Physicians using hydroxyurea must be aware of its potentially life-threatening pulmonary toxicity.